How to draw fungus in Rhino
- create two surfaces 'from network of curves' (cirkels and open curves)
- copy the outer surface
- use 'blend surface' to connect the inside and the outside surface and 'create solid'
- paste the outside surface and 'extract wireframe', 'trim' and 'tube' the vertical lines
- use 'boolinan difference' to remove the tubes and create the gills
